BP Crews Prepare Containment Dome to be Lowered Over Gulf Oil Leak

Crews prepared today to lower a 100-ton box they hoped would cut off most of the crude spewing from a blown-out well in the Gulf of Mexico, the urgency of their task underscored by oil that started washing up on delicate barrier islands.

If the concrete-and-steel box works, it could collect as much as 85% of the leaking oil. Workers hope to have the device on the seabed this evening, but it will likely be Sunday or Monday before it's fully operational and they know if it's working.

Remotely operated vehicles (ROVs) cut the broken end of the drill pipe to ensure a clean end, and successfully attached a half-ton valve. This is not expected to reduce the overall flow of oil from the well but BP says this will “simplify” the problem and allow it to focus its efforts on the remaining two leaks.